Checked all of the rod bearings and they were all pretty much the same. Found two score marks on the bearings but not on the journal. One of the shells popped out and I found they were made by Clevite and the crank appears to have been ground.010. So off to order new bearings and button up the bottom end.

Mike

Thanks Ted. The wear pattern is on one side only and not even across the bearing surface. Either width or lengthwise. That is why I figured they were toast. I have a digital caliper that should get me close readings. But I am no machinist that is for sure. The next thing up is a main and I am assuming g they will come out similarly. I have the sinking feeling that she is going to make a long trip to see Tim the Y block guy……

Mike

It may be an optical illusion in the pictures you posted but the bearing wear looks to be the result of too much clearance.  I have placed arrows on what the pictured wear pattern looks like on my end.  It should be wider than what the arrows show.  Doing a micrometer check of the crankshaft journal will give you an idea if that particular rod journal is undersize more than it is suppose to be.
  

  

Lorena, Texas (South of Waco)

1/5 rod caps. I think they are bad or are they salvageable?

you can see numbers stamped on main caps so its a rebuilt.the steam holes in the block were a giveaway at any rate.

Ok, should I pull a main cap or two to check/plasti gauge the main bearings? On the one hand I can check clearances but on the other hand if the block is cracked due to that 56 misprint then I disturbed the crack. Dad suggested just checking #1/8 those being the furthest and hottest cylinders. Any ideas?

Mike

1958-1959-1960 Mercurys had a 312 Engine (standard equipment) with 471 cylinder heads and a 2bbl, the blocks were  ECZ or B9AE. look for a casting date on the block that will help.
  

Got the valley an oil pans off, not to bad. It has 312 caps🎉🎉. Some sludge but not too bad. So as long as the bearings are good, I will regasket her and button her up.

Mike

So, since this engine has been opened-at least on the top end so far-it has become a Frankenstein motor. Not that that is bad, but just not what I was hoping for. I checked the numbers on the block, heads, exh and intake manifolds and I get different years. This is what I got:

Block= ECZ 6015C=292/312
Exhaust manifolds R=B9AE, L=EDB (58-59 292 manifolds)
Water outlet=ECE-8/3
Intake=ECZ-9425-B

So my guess is this, the engine is a genuine low mileage 312 (well at least at this point in time) that went to the fairlane I got it out of. But at some point the heads and manifolds got replaced along with the valley pan. The only reason I say this about the pan is that it was designed with a PCV valve in it from the factory. It has a stamped indentation where the valve sits so I don't think it is a later mod.

Mike

ECZ-6015-C is a 1957 292-312 block. The dot on the C/S identifies the crank as being 312. You need to verify main caps as someone may have cut a 312 crank into 292 block. A set of correct heads (non-posted) should be readily available.

The CARB is a FORD 4100 4V with an electric choke of all things.

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